I bought a (used) 3 horse slant load ponderosa trailer that was 6' wide and quickly found out that neither one of my horses would fit in between the dividers.  I could shut the divider on one, but he was way to cramped to actually haul him that way.  I couldn't even shut the door on my mare (she was too long to fit).  I'm shoppping for a new trailer but want to make sure I get one my horses will comfortably fit in.  I'm considering the Titan Avalanche II which is 6'8" wide with the stalls being 40" wide.  I'm having a hard time thinking that an extra 8" would make enough difference.  So what do you think . . . Has anyone had problems fitting bigger horses within these dimensions?  My horses aren't tall, but they are about 1200 lbs each and long.

What size are your horses?  I have a Titan Avalanche GN 3H slant.

The BEST way to see if your horses will fit in any slant trailer is to stand your horse relaxed. Measure from nose to butt.  Use THAT measurement. Then, measure the length of the slant divider. Do NOT use any other measurement that a brochure or salesperson gives you for length.

I haul my 15.1h 1200 pound QH comfortably in my slant trailer. He wears a 76-78 blanket. However, I am also able to remove the divider between the front and middle stall and then give him 2 stalls for long hauls.

to haul a 16.1 hand Belgian draft - because of his bulk, he needed 2 stalls or no dividers. His length was okay, since Belgians hold their heads a little higher when relaxed, but his bulk was too snug and my dividers have no padding on them. But... perhaps a 16.1 hand T'bred or similar built horse would be fine.

The last stall in trailers will generally be a little more roomy. 

One thing about slants with no rear tack... be sure they have a safety chain for the full width of the rear so that the horses are not leaning on the rear doors.